With the diffusion of highways, the demand for tires having a self-sealing function has been increasing day by day, and various self-sealing tires with a puncture sealing layer have been proposed heretofore. Conventionally, there has been proposed, for example, a self-sealing tire in which a high viscosity adhesive is applied as a sealing material to the inner surface of the tire crown portion to form a puncture sealing layer. The tire of this type, however, involves a problem that, when the tire turns at a high speed, the adhesive can not seal a puncture in the vicinity of the shoulder portions, because it flows to the center side of the crown portion by a centrifugal force.
Conventionally, there has been proposed, for example, a self-sealing tire in which a high viscosity adhesive is applied as a sealing material to the inner surface of the tire crown portion to form a puncture sealing layer.
The tire of this type, however, involves a problem that, when the tire turns at a high seed, the adhesive can not seal a puncture in the vicinity of the shoulder portions, because it flows to the center side of the crown portion by a centrifugal force.
Japanese Patent Laid-open No. 1979-6206 discloses a self-sealing tire in which a sponge layer impregnated with an adhesive similar to the aforementioned is affixed to the inner surface of the tire crown portion to form a puncture sealing layer. The puncture sealing layer of this tire is formed such that, after attaching a sponge layer to the tire inner surface, an adhesive is impregnated into the sponge layer from one surface thereof by means of press rollers with the tire being rotated.
Consequently, in order to fully impregnate the sponge layer with the adhesive so that it reaches the tire inner surface, it is necessary to turn the tire at a low speed and to provide a high pressing force. As a result, the working time for impregnation of the adhesive increases, thereby deteriorating workability.
Since the adhesive is exposed on the surface of the sponge layer, dust and foreign object stick thereto during transporting, stocking and the like, thereby deteriorating its appearance, and the adhesive adheres to a hand of the operator and equipment during handling of the tire, thereby making it bad to handle the tire.